The present invention relates to a dropper adaptor for a bottle, of the type comprising a plastic body passed through longitudinally by a flow channel.
Adaptors of this type, intended in particular to be fitted to bottles of ophthalmological products, should be capable of delivering the product dropwise, without pressure, even if the user creates a relatively high pressure in the bottle, which is generally made of flexible plastic.
In order to obtain an adaptor at a low cost price, it is sought to produce the channel so that the channel itself creates the head loss necessary for obtaining the dropper function. For this purpose, in the conventional technique, the channel is generally made with a circular cross section with a diameter that decreases inwards, that is to say towards the inside of the bottle in use, the entry diameter of the channel being of the order of 0.2 mm for example.
Now, in practice, it is difficult to obtain such channels reliably in industry with a high production rate. In fact, it is necessary to arrange in the injection mold of the adaptor a needle whose tip is correspondingly fine, and a non-negligible frequency of breakage of the needle is observed during injection of the plastic.